Synthesis, characterisation and thermal degradation behaviour of some coordination polymers by using TG–DTG and DTA techniques

Abstract

The four chelate polymer complexes commonly called as coordination polymers of Mn(II), Co(II), Ni(II) and Cu(II) ions with fbpmpc (fbpmpc = fumaroyl bis (paramethoxyphenylcarbamide)) were synthesized and characterised by elemental analyses, infrared spectroscopy, diffuse reflectance, magnetic moment susceptibility, thermal analysis, X-ray diffraction, electrical conductivity and scanning electron microscopy technique (SEM). SEM investigations of coordination polymers were found in different shapes and sizes, though they are synthesized from a single ligand. Each metal ion is coordinated by a bis (bidentate) manner through oxygen atom of the carboxylato group and the nitrogen atom of an amide group of ligand and two aqua ligands by coordinated bond which formed 6-member heterocyclic ring. In the present article, the main aim of research study is to find out the comparative studies of coordination polymers such as thermogravimetry (TG), derivative thermogravimetry (DTG), differential thermal analysis (DTA), electrical conductivity and morphology behaviour. Furthermore, the electrical conductivities of chelating ligand and coordination polymers were determined in the solid state powder form. The electrical conductivities measurements of undoped and doped ligand, coordination polymers were carried out at room temperature by the four probe technique using an electrometer. Thermal degradation studies of the coordination polymers have been carried out from a non-isothermal condition under nitrogen atmosphere at a heating rate of 10 °C min−1. The decomposition steps and thermal stabilities of these complexes were confirmed by thermal analysis techniques (TG/DTG/DTA). The thermal studies inferred the presence of crystallized water in all coordination polymers, whereas coordinated water was found in Ni(II) and Cu(II) ions.

Keywords

• Coordination polymers
• Fumaroyl bis (paramethoxyphenylcarbamide)
• SEM
• TG/DTG/DTA techniques
• Electrical conductivity
• Thermal stability